Thread laying mechanism for precision winding of pineapple bobbins

ABSTRACT

A slider on a movable adjusting guide bar to reduce the traverse distance of the yarn guide as the diameter of the bobbin increases, cooperates with a slider in a fixed track driven by a grooved roll. To prevent undesired jarring upon reversal of traverse direction, a damping device, e.g., a cylinder and piston damping arrangement is provided, one end thereof being fixed and the other end linked to a point of the adjusting guide bar.

United States Patent [191 Gerber [451 Oct. 9, 1973 THREAD LAYINGMECHANISM FOR PRECISION WINDING OF PINEAPPLE BOBBINS [75] Inventor:Robert Gerber, Horgen, Switzerland [73] Assignee: MaschinenfabrikSchweiter AG, I

Horgen, Switzerland [22] Filed: June 15, 1972 [2]] App]. No.: 262,993

[30] Foreign Application Priority Data June 30, 1971 Switzerland 9639/71[52] [1.8. CI. 242/43.l [51] Int. Cl B65h 54/32 [58] Field of Search242/43, 43.1

[56] References Cited UNITED STATES PATENTS 2,206,582 7/1940 Shipman242/43.l

8/1942 Treckman 242/43.1 10/1967 Marciniak 242/43.l X

Primary Examiner-Stanley N. Gilreath Attorney-Flynn & Frishauf ABSTRACTA slider on a movable adjusting guide bar to reduce the traversedistance of the yarn guide as the diameter of the bobbin increases,cooperates with a slider in a fixed track driven by a grooved roll. Toprevent undesired jarring upon reversal of traverse direction, a dampingdevice, e.g., a cylinder and piston damping arrangement is provided, oneend thereof being fixed and the other end linked to a point of theadjusting guide bar.

3 Claims, 1 Drawing Figure This invention relates to a thread layingmechanism for the precision winding of so'-called pineapple bobbins. Itrelates more particularly to precision cross winding machines in whichthe traverse mechanism uses a slider reciprocally moved in its track bya grooved traverse roll and carrying the pivot of a bell crank, one armof which carries a yarn guide and the other of which is constrained bythe movement of a second slider carried on its extremity, which movesback and forth in an adjusting guide bar, the angular position of whichis controlled by a winding bracket in response to the diameter of thebobbin being wound in such a way that the thread lay reversal points areshifted closer together as the bobbin diameter increases.

In the winding of pineapple bobbins, which are bobbins, the end surfacesof which are tapered outwardly, by means of thread laying mechanisms ofthe type just described and heretofore known, the difficulty arises thatthe inertia of the yarn guide and its bell crank resulting from the massof these components exerts a mechanical shock on the adjusting guide barin the direction of swing of the latter on each reversal of direction ofthe slider driven by the grooved traverse roll. Quite apart from theincreased wear of the components involved thus arising, this behavior ofthe machine generally impairs the quality of the bobbin by producingirregularities in the end surfaces of the winding.

lt is an object of this invention to prevent the adjusting guide barfrom receiving a kick on each reversal of the direction of the yarnguide and thereby will make possible the winding of pineapple bobbinswith tapered surfaces of high regularity and greater precision.

SUBJECT MATTER OF THE PRESENT INVENTION Briefly, between a point of theadjusting guide bar longitudinally offset from its fulcrum and areference point which, like the said fulcrum, has a fixed relation tothe machine frame, a clamping device is provided in such a way that itis effective in the direction of swing of the adjusting guide bar. Sincethe adjusting guide bar is adjustable over a predetermined limitedangular range, the damping element is preferably composed of a pistonand cylinder arrangement in which the region of the damping movement isautomatically shifted in accordance with the particular angular settingof the adjusting guide bar. To provide compact construction, the dampingdevice is preferably connected to the ad justing guide bar by means of asecond bell crank pivoted on a fixed point of the machine, in such amanner that one crank arm may be moved by the end of the adjusting guidebar connected to the winding bracket and the other crank arm has aswivel connection with the damping device.

In order that optimum effective damping may be obtained with minimumvariation of the setting of the adjusting guide bar, the aforesaidsecond bell crank is arranged so that over the adjustment range of theadjusting guide bar, the arm of the bell crank connected to theadjusting guide bar, is directed approximately parallel to the adjustingguide bar, while the other arm of the bell crank is directedapproximately perpendicular to the direction of operation of theclamping device.

An illustrative embodiment of the invention will be more particularlydescribed with reference to the accompanying Drawing, which is aperspective schematic view of a thread laying mechanism. 1

As shown in the drawing, the thread laying mechanism for windingpineapple bobbins on a precision cross winding machine comprises amotor-driven traverse roll 1 with guide grooves 2. Guide rails 3a (shownwwth right end cut away) and 3b parallel to the axis of roll 1 can serveto fix the path in which the slider 4 is caused to move back and forthover substantially the entire length of the roll 1. The movement of theslider 4 is produced by a follower 5 in the form of a stud extendingdownwardly from the underside of slider 4 into the grooves 2 of the roll1.

A bell crank 7 is pivotally mounted on a bearing 6 carried by slider 4.One arm of bell crank 7 carries'the yarn guide 8 which moves back andforth in synchronism with the'slider 4 and lays a thread (not shown) ona rotating bobbin (likewise not shown). ln order .that the reversingpoints of the thread traverse on the bobbin may be shifted towards themiddle of the bobbin in response to increasing diameter of the bobbin,which is a requirement for so-called pineapple bobbins, the other arm ofbell crank 7 carries a second slider 10 with a swivel mounting on abearing 9. This second slider 10 is movable back and forth in the guidechannel of an adjusting guide bar 11. I

in the illustrated embodiment of the invention, the adjusting guide bar11 has a swivel mounting in its mid portion on a bearing 12 fixed withrespect to the machine frame which allows it to be swung in a planeparallel to the directions of movement of sliders 4 and 10. As shown inthe drawing, the bearing 12 is provided by a stud on theprojecting endof a bracket 13mounted on guide rail 3a.

The left end, as shown in the drawing, of adjusting guide bar 11 isforked so as to be able to engagea stud (not shown) mechanically linked(by means not shown) to the winding (likewise not shown). The windingbracket rides on the surface of the bobbin being wound and, moving withthe latters increase in diameter, controls the angular position ofadjusting guide bar 11 relativeto the guide rails 3a and 3b so that withincreasing diameter of the bobbin the adjusting guide bar 11 is swungmore and more out of parallelism with guide rails 3a and'3b, for examplecounter-clockwise. As a result, the two reversal points of yarn guide 8are shifted inward, as desired. a

In order to provide camping of the kick transmitted to adjusting guidebar 11 upon reversal of the movement of slider 4 as driven by traverseroll 1, a damping device is provided which suitably comprises a cylinder15, shown partly cut away, and a piston 17 movable therein by means of apiston rod 16. The path of the damping movement of piston 17automatically adjusts itself to changes in the position of themechanism. The

free end of piston rod 16 has a swivel mounting on a pivot 18 which hasa fixed position with respect to the machine frame. As illustrated, thepivot 18 is located on bracket 13. Cylinder l5, furthermore, also has aswivel mounting, in this case provided on one arm of a second bell crank19, of which the other arm engages one end of the adjusting guide bar 11by means of a stud 20 in the fork 14. The pivot 21 of this second bellcrank 19 is located on a second bracket 22, shown in the drawing to theleft of first bracket 13 on guide rail 3a, the position of which isfixed with respect to the machine frame.

By virtue of this arrangement, the damping device 15, 16, 17 can freelychange its position to correspond with the angular adjustment ofadjusting guide bar 11 so as to optimize the position of its dampingeffect to the adjusting guide bar 1 1. For this purpose, bell crank 19is so fashioned and its pivot 21 is so disposed that over the range ofangular adjustment of adjusting guide bar 11 the arm of bell crank 19which engages fork 14 is as nearly as possible parallel to adjustingguide bar 1 1 and the crankarm connected to cylinder 15 is as nearly aspossible directed at right angles to piston rod 16. This permits theposition of an elongated damping device more or less parallel toadjusting guide bar 1 1, thus providing a conveniently compact form ofconstruction.

It will readily be seen, however, that bell crank 19, or dampingcylinder 15 directly, could be connected to other positions on adjustingguide bar 11 and, likewise, the fixed pivots l8 and 21 of the clampingdevice could be located at other positions. Instead of the pistons andcylinder damping device shown, moreover, other damping means, forexample spring means, could be used.

1 claim:

1. A thread laying mechanismfor precision winding of pineapple bobbinscomprising: 7

a grooved traverse roll and driving means therefor;

a first slider mounted in a fixed rectilinear guide and having afollower stud engaging said traverse roll to provide reciprocatingmovement to said slider;

a bell crank pivotally mounted on said first slider carrying on one ofits arms a yarnguide and on its other arm a second slider, said secondslider being held reciprocally movable in a channel of an ad' justingguide bar which is pivotally mounted on a fixed bearing and is arrangedto have its position controlled at least at one end, through mechanicallinkage to a winding bracket, in accordance with the diameter of thebobbin being wound, whereby the traverse length may be progressivelyreduced with increase of said diameter; and

a damping device connecting a point of said adjusting guide bar offsetfrom its said bearing to a fixed point of the machanism, said dampingdevice being arranged so as to operate in the direction of swing of saidadjusting guide bar, the damping device being pivotally connected withsaid adjusting guide bar by means of a second bell crank which ismounted on a fixed bearing, whereby one arm of said second bell crank ismovable by the end of said adjusting guide bar which is connected tosaid winding bracket and the other arm of said second bell crank ispivotally connected with said clamping device.

2. A thread laying mechanism as defined in claim 1, in which saidclamping device comprises a cylinder and a piston mounted therein andwhich is so arranged that the path of the damping movement isautomatically adjusted.

3. A thread laying mechanism as defined in claim 1, in which said secondbell crank is so arranged that in the angular adjustment range of saidadjusting guide bar the arm of said second bell crank connected to saidadjusting guide bar extends roughly parallel to said adjusting guide barand the otherarm of said second bell crank extends roughlyperpendicularly to the operating direction of said damping device.

1. A thread laying mechanism for precision winding of pineapple bobbinscomprising: a grooved traverse roll and driving means therefor; a firstslider mounted in a fixed rectilinear guide and having a follower studengaging said traverse roll to provide reciprocating movement to saidslider; a bell crank pivotally mounted on said first slider carrying onone of its arms a yarn guide and on its other arm a second slider, saidsecond slider being held reciprocally movable in a channel of anadjusting guide bar which is pivotally mounted on a fixed bearing and isarranged to have its position controlled at least at one end, throughmechanical linkage to a winding bracket, in accordance with the diameterof the bobbin being wound, whereby the traverse length may beprogressively reduced with increase of said diameter; and a dampingdevice connecting a point of said adjusting guide bar offset from itssaid bearing to a fixed point of the mechanism, said damping devicebeing arranged so as to operate in the direction of swing of saidadjusting guide bar, the damping device being pivotally connected withsaid adjusting guide bar by means of a second bell crank which ismounted on a fixed bearing, whereby one arm of said second bell crank ismovable by the end of said adjusting guide bar which is connected tosaid winding bracket and the other arm of said second bell crank ispivotally connected with said damping device.
 2. A thread layingmechanism as defined in claim 1, in which said damping device comprisesa cylinder and a piston mounted therein and which is so arranged thatthe path of the damping movement is automatically adjusted.
 3. A threadlaying mechanism as defined in claim 1, in which said second bell crankis so arranged that in the angular adjustment range of said adjustingguide bar the arm of said second bell crank connected to said adjustingguide bar extends roughly parallel to said adjusting guide bar and theother arm of said second bell crank extends roughly perpendicularly tothe operating direction of said damping device.